How do I request a quotation for swing system parts, and how fast is the reply?

Send the machine model and serial number, the part number or nameplate photograph of the old swing motor or reduction assembly, clear photographs of the failed component, the quantity and the destination port to Guangzhou Shenyue Machinery Technology Co., Ltd. Quotations normally come back within 24 hours, with every line marked genuine, OEM-quality or aftermarket.

How do I know whether the swing bearing or the reduction gearbox is failing?

Gearbox failure announces itself through the oil: metal particles on the magnetic drain plug or a whining noise under swing load point inside the reduction. A failing slewing ring is quieter — uneven play measured at the carriage, grease containing flakes, and crunching while slewing on a slope. Photographs of what the drain plug picks up are often enough for a first diagnosis.

Can the reduction be bought as gears only instead of a complete assembly?

Yes. When the housing is sound, the planetary gears, shafts and bearings can be replaced as a set at a fraction of the cost of a complete reduction assembly. The choice between gears-only and complete assembly is confirmed from photographs of the old unit before the order is placed.

Excavator Swing Bearing and Swing Reduction Gearbox: What Wears, What to Replace

Product Guide · October 3, 2026 · Guangzhou, China

Swing Bearing (Slewing Ring) and Swing Reduction Gearbox: A Cross-Brand Buying Guide

Swing reduction gears and shafts supplied as individual parts

Swing reduction parts, bearings and shafts from a mixed export order

Swing reduction assembly checked before dispatch

Nothing on an excavator is taken for granted like the swing. The upper structure turns thousands of times a day, and when it starts to protest — crunching, play, a swing that hesitates under load — the repair decision spans three separate components with three separate price tags: the slewing ring (swing bearing), the swing reduction gearbox, and the swing motor. Choosing the right one of the three is the difference between a two-day repair and an unnecessary five-figure overhaul. This guide separates them, brand by brand.

Corbay is the international export brand of Guangzhou Shenyue Machinery Technology Co., Ltd., Guangzhou, China. The company supplies swing system components — slewing bearings, slewing gear assemblies, reduction gears, shafts and swing motors — across Kobelco, Sany, Caterpillar, Komatsu, Hitachi, Doosan and other machine brands, with 3,000+ part types on the shelf and every quotation marked genuine, OEM-quality or aftermarket.

Three Components, Three Different Failures

The slewing ring (swing bearing).A large gear ring between the carrier and the upper structure. It wears slowly and quietly: play measured at the carriage, flakes in the grease, crunching on a slope. Slewing bearings of this type are produced by specialised bearing makers — SKF publishes the engineering principles behind them — and the bearing is matched to the machine by the number stamped on the ring.

The swing reduction gearbox.A planetary reduction bolted to the carrier, multiplying swing motor torque into the pinion. It fails through its oil: metal on the drain plug, whining under load, and eventually a swing that stalls. Gears, shafts and bearings can be replaced individually when the housing is sound.

The swing motor.The hydraulic motor driving the reduction. It fails through speed and drift: the upper structure swings slower over weeks and overshoots or drifts when stopping. Motor assemblies and their internal parts are quoted from the motor's own nameplate.

Why the order matters.A gearbox run with a failing bearing, or a motor run on a failed gearbox, damages the new part quickly — so the diagnosis should name the component before the order is placed.

What the Numbers Look Like on Real Machines

On the Kobelco 20-tonne class, the slewing gear assembly commonly referenced for SK200-8 machines is YN40F01001P1, with related references YN40F00033F2 and YN40F00026F1, and the SK380-10 class carries its own swing slewing reference, LC40F00027F1. Swing motors are quoted separately: the SK200-8 class commonly references YN15V00077F1 / YN15V00055F1 / YN15V00035F1 (M5X130 class), while the SK330-8 class commonly references LC15V00022F1 (M5X180 class). For other brands — Sany, Caterpillar, Komatsu, Hitachi, Doosan — the bearing ring number, the gearbox number or the motor nameplate is the starting point, and anything not yet catalogued is quoted as commonly referenced, with the nameplate as the authority. The swing and travel category lists stocked lines, and the swing reduction assembly page shows how a complete reduction is presented with its fitment range.

Gears Only, or Complete Assembly?

Complete reduction assembly.Fastest repair, highest cost — the right call when the housing or several planets are damaged.

Gears, shafts and bearings as a set.The common middle path when the housing is sound; photographs of the opened gearbox decide it.

Bearing only.Correct when the play is measured at the ring and the gearbox oil is clean — but the pinion mesh should be inspected while the machine is open.

Grade in writing.Genuine, OEM or aftermarket — marked on every line of every quotation from Guangzhou Shenyue Machinery Technology Co., Ltd.

What to Send for a Swing-System Quotation

Machine model and serial number, the number or nameplate photo of the failed component, photographs of what the drain plug picked up, quantity and destination port. That is enough for the technical team — each member with more than ten years of Kobelco parts experience — to confirm the correct reference and return a priced quotation within 24 hours, usually with alternatives across grades where they exist.

Order Swing Parts — FAQ

Do you supply swing parts for Chinese and Korean brands too?Yes — Sany, XCMG, Doosan and Hyundai swing components are quoted from the same warehouse alongside Japanese brands, in one consolidated shipment when needed.

How are heavy items packed?Bearings and reductions are packed in export-grade wooden cases with photographs sent before the goods leave, and sea freight is quoted alongside air for heavy pieces.

How fast is the reply?Quotations normally come back within 24 hours of a complete enquiry — nameplate photo, quantity, destination port — through the contact page.

Request a Swing-Parts Quotation Browse Swing and Travel Parts

Corbay Excavator Parts is the international export brand of Shenyue Machinery (Guangzhou Shenyue Machinery Technology Co., Ltd.), Guangzhou, China. Shenyue is an independent parts specialist and is not affiliated with, or an authorized dealer of, Kobelco Limited. Parts are supplied as genuine, OEM or clearly identified aftermarket items, and the grade is stated on every quotation.